The prospects for a grand bipartisan debt deal may depend in large part on the personal marketing skills of Sen. Saxby Chambliss.

Can the folksy Georgian persuade his fellow Republicans, including his buddy Speaker John Boehner (Ohio), to embrace a tax reform package that lowers rates but raises revenue to cut the deficit?

The idea is a key component of the $4 trillion plan backed by a majority of President Barack Obama’s fiscal commission, which the “gang of six” Senators, including Chambliss, are using as a framework to reach a grand bargain.

But Chambliss has his work cut out for him. Boehner and Senate Minority Leader Mitch McConnell (R-Ky.) both warned Tuesday that they don’t support any tax increases as part of a bipartisan deficit deal before Obama’s deficit speech today. And conservative critics have blasted the commission plan as a tax increase dressed up as tax reform.

Still, the 67-year-old lawmaker is cautiously optimistic — and he starts by selling the commission plan as a tax cut for most people that would boost economic growth even though revenue would increase by a net of hundreds of billions of dollars over the coming decade because many deductions would shrink or disappear.

People who call that a tax increase “don’t know what they’re talking about,” Chambliss said Tuesday during an interview in his Russell office. “We’re not talking about raising taxes. ... It’s people who want to be relevant is the only way I can figure it,” Chambliss said of his critics. “We’re talking about lowering tax rates.”

Chambliss said he’s “very optimistic we’ll be able to have as many Republicans as Democrats” vote for the gang of six’s plan when they come out with one, and that ultimately the House will go along.

“John [Boehner] and I have had conversations about the fact that solving this problem is going to be very, very difficult. We have not gotten into the specifics of it,” Chambliss said. “Ultimately I’m hopeful that Republicans in the House and Democrats in the House will see that this problem is so serious and the only way you are going to solve it is to look at the three pillars — cuts in discretionary, entitlement reform and revenue reform.”

Chambliss may appear from afar as an unlikely bipartisan warrior. Some Democrats are still smarting from his 2002 unseating of then-Sen. Max Cleland (D-Ga.), and he has a conservative voting record. But it’s not his first bipartisan rodeo.

Senate Budget Chairman Kent Conrad (D-N.D.) noted that they worked closely to clear the way for the 2007 farm bill, and the duo teamed up again on the “gang of 20” bipartisan group on energy. Chambliss also worked on bipartisan efforts on immigration.

Chambliss said that’s the reality of being effective in the Senate.

“I take the attitude I wasn’t sent here to just vote ‘no’ for the next two years,” he said.

Chambliss and the other “gang” members — Conrad, Majority Whip Dick Durbin (D-Ill.) and Sens. Mark Warner (D-Va.), Mike Crapo (R-Idaho) and Tom Coburn (R-Okla.) — were buoyed recently by a letter from 64 Senators — 32 Republicans and 32 Democrats — praising the gang of six and urging Obama to lead on a deficit-reduction plan including tax reform.

The gang actually started much smaller, with a conversation on the Senate floor between Warner and Chambliss last year during a lull in votes.

“When we started this, it was kind of the two of us and it was a human interest story,” Warner said. “Then it became six and then 64 on the letter.”

“We started a process to educate ourselves,” Warner said. “The size, scope and imminence of the problem ... made us say, ‘Hey, we gotta both get out of our comfort zones.’”

The group is going to include a provision to require that any extra revenues coming into the Treasury as a result of faster economic growth go to deficit reduction and lower tax rates, not more spending, Chambliss said.

“That is a key ingredient in our proposal,” he said. “If you get additional money into the Treasury, historically, Congress will spend it. ... We’ve got to make sure that conservatives understand it’s not going to be available to be spent.”

The public also has to be sold on the concept. Chambliss said wealthy people have told him they would be OK with paying more taxes if it would reduce the deficit, but not for more spending.

“On both ends, salesmanship has to take place,” Chambliss said.

Republicans also need to understand that a plan such as the proposal by House Budget Chairman Paul Ryan (R-Wis.) to cut $6 trillion from spending alongside more tax cuts simply won’t fly, Chambliss said.

“It’s a serious proposal, but it’ll never pass the Senate,” Chambliss said.

Warner and Chambliss have forged the type of bipartisan relationship that is somewhat of a throwback to more collegial times.

“All of these partnerships start with trust,” Warner said. “I trust him and I know he’s got the country’s interests first. There’s a lot of folks in the Senate who are always first to the microphone. I think Sen. Chambliss is somebody who when he talks, people listen.”

And he praised Chambliss for sticking to the tax reform idea. “He’s really been a rock,” he said.

Warner said Chambliss has been more deliberative and patient and has a better sense for how to develop a coalition.

“He understands the rhythms of the Senate. ... I’m much more impatient.”

Chambliss said his approach is to ask experts what is needed and work to build bipartisan bridges so they can become law.

“I’m not necessarily an idea guy,” he said.

Still, Chambliss said, the scope of the problem isn’t that hard to figure out.

“This is not rocket science to figure how big of a trouble we’re in,” he said.